Dental articulator



June 8 1926.

R. W.l BURCH DENTALARTICULATQR Filed March 24, 1923 Patented `lune A8,1926.

4 UNITED STATES.

PATENT. onirica...

RAYV'W'. BUR'CH, 0F FORT LAUDERALE,

DENTAL ARTCULATOR.

.l `applicati@ sied March 24, 1923. serial No. 627,520.

This invention relates to dental articii` lators and more particularlyto a device which will reproduce the artici'ilatorymove-V ments of thehuman jaws.

The principal object of the invention .is toprovide a device of thischaracter in which plaster lcasts having artificial teeth therein can bemounted and means to speedily grind the teeth in' order to permit thenatural functioning of the mouth.

The operation of this articulator is basedy 'largely on the theory thatthe path of the atory moving mandible is determined artcu t as though itmoved on the outer surface of an eight inch sphere; that is the twocondyles and the cusps ofthe teeth contact as if on the surface of thesphere during all the ar.- ticulatory movements.

VWhen the articulator is manipulated the upper plate holding themandible cast will move 'forward and then execute a laterall chewingmovement Vthereby producing a' spiral action ofthe plate. f

This spiral movement acting in combination with the interlocking of thecusps will produce a milling action and reproduce the articulatorymovements of the human jaw and grind the artilicial teeth in the properkand correct manner for the eiicient crushing of the food.l n

F or a more detailed understanding of the invention attention is nowcalled to the drawings in which a preferred embodiment is shownillustrated. In these drawings like parts are designated by likereference characters in all the views.

Fig. 1 is a perspective view of the dental articulator. f

Fig. 2 is a top plan view thereof. Fig. 3 is a section on line 3-3 ofFig. 2. Fig. 4 is a front view. Fig. 5 is a fragmentary top view. l

Fig. 6 is a detail of the eccentric and camy Fastened tothe shaftadjacent the lbeariings 5.are eccentrics 9 parallel lto each `other andatan angle to the shaft 3 and with their limit of throw reverselyarranged. Integral withthe eccentric's are carnslO having a` ridge 11 inthe center` and sloping sides12 and 13. Y j l As noticed'in Fig. 6`underneath the upper plate member 2 and'coacting with y'the crains 10are projections 1,4 which bear against the surfaces l13 of the cam.`Integral with the said plate member are arms 15 "having screws 16therein which "bear against the surfaces 12' of the cain. v Adjacent thescrews 16 are wing nuts' 17 which alternately bear against the peripheryof the eccentric 9.A f

Attached to the arm 8 asnoted 'in Fig. 3 is a flat spring 18 which bearsaround the shaft 3 and resiliently vforces the upper plate mein-y ber 2against the cams 10.

Numeral 19 represents a'pair ofarins and 20 a ridge onthe tip of thebottom plate for Y ysup porting the cast.

y'The operation of this device `is as follows.

The casts having the teeth imbedded are fastened to the upper and lowerplates re'- spectively and the lrnob 21 turned. This will cause theshaft, eccentric'9 and cams 10 to revolve. i The eccentrics coming incontact with the wing nuts 17 alternately will impart a circular`movement in a horizontal `plane of the casts supported by the upperplate memberwhich corresponds to the cir- -cle A in the diagram shown inFig. 7. This motion can be increased orfdecreased by adjusting the setscrews 16. f At the same time a rocking motion will be imparted to thecast which corresponds to the circle B and is at right angles to thecircle A. vThis last movement is caused bythe lugs 14 alternately movingupward and downward on the n slope 13 of the cams l0.

Having thusdescribed my `invention what I desire to secure by LettersPatent is:

l. Ina dental articulator, upper and lower plate membersa a commonshaft, means to move the upper plate member in a horizontal plane so thesaid member will describe a circle and means to move said platememberfor describing a circle in a plane substantially at right anglesto the first mentioned circle, the said means including eccentricsandcams on the said common shaft and means coacting with the saideccentrics and cams.y

2. In a dental articulator a base, an upper upper. plate member so thesaid member describes a circle simultaneously in a vertical andhorizontal plane, the said means including eccentrics and cams on thesaid common shaft, and means coacting with the said eccentrics and cams.

4l. In a device of the class described in combination, a base, side armsforming a bearing, a shaft, eccentrics and cams fastened to said shaft,a movable upper plate member, lugs on the said upper plate membercoacting with the said cams and means resilientl7 forcing the said-*lugsand cams in Contact with each other.

-5. In a dental articulator, the combination of a base, side armsforming a bearing, a shaft, eccentrics and cams on said shaft, a movableupper plate member,.lugs on the said plate member coaoting withy thesaid cams and a springfor resiliently forcing the said lugs against thesaid cams.

6. In a device of the class described in combination, a base, side armsforming a bearing, a shaft, eccentrics and cams on said shaft, Van upperplate member, side arms integral with they said plate member, set screwsin said side arms and a spring resiliently forcing the said upper platemember against the said shaft.

7. In a dental articulator having a base,

ylower member, arms integral wit-hfthe ksaid 5.0

lower member eccentrics and cams on said shafts, lugson the said upperplate member coacting with said cams, and resilient means for forcingthe said cams and lugs in `contact with each other, ay movable uppermember, a shaft passing through the upper part of the said arms, a ridgeat the toe of the said stationary lower memberadjustable side armsattached to the said stationary member', the said ridge and side arms 50adap-ted to hold plaster casts in definite relation to the said lowermember and means to move the said movable upper member.

RAY W. BU RCI-rl.

